Characterization of lysine acetylation in the peripheral subunit-binding domain of the E2 subunit of the pyruvate dehydrogenase-2-oxoglutarate dehydrogenase hybrid complex from Corynebacterium glutamicum

Abstract

In Corynebacterium glutamicum, pyruvate dehydrogenase (PDH) and 2-oxoglutarate dehydrogenase (ODH) form a unique hybrid complex in which CgE1p and CgE1o are associated with the CgE2–CgE3 subcomplex. We analyzed the role of a lysine acetylation site in the peripheral subunit-binding domain of CgE2 in PDH and ODH functions. Acetylation-mimic substitution at Lys391 of CgE2 severely reduced the interaction of CgE2 with CgE1p and CgE3, but not with CgE1o, indicating the critical role of this residue in the assembly of CgE1p and CgE3 into the complex. It also suggested that Lys391 acetylation inhibited the binding of CgE1p and CgE3 to CgE2, thereby affecting PDH and ODH activities. Interestingly, the CgE2-K391R variant strain showed increased l-glutamate production and reduced pyruvate accumulation. Kinetic analysis suggested that the increased affinity of the K391R variant toward pyruvate might be advantageous for l-glutamate production.

Proteomics and Lysine Acetylation Modification Reveal the Responses of Pakchoi (Brassica rapa L. ssp. chinensis) to Oxybenzone Stress

“…In addition, malate dehydrogenase (MDH1), α-oxoglutarate dehydrogenase (OGDH), and isocitrate dehydrogenase (NAD + ) (IDH3), which are involved in the TCA cycle, were significantly acetylated under oxybenzone treatment. It has been shown that acetylation can activate the activity of MDH. , The activity of the 2-OG dehydrogenase complex may also be affected by acetylation of the peripheral subunit-binding domain of the E2 subunit of the pyruvate dehydrogenase-2-oxoglutarate dehydrogenase hybrid complex, while the acetylation of IDH will have an impact on the distribution of carbon flux between the glycolysis and gluconeogenesis pathways …”

“…It has been shown that acetylation can activate the activity of MDH. 52,56 The activity of the 2-OG dehydrogenase complex may also be affected by acetylation of the peripheral subunitbinding domain of the E2 subunit of the pyruvate dehydrogenase-2-oxoglutarate dehydrogenase hybrid complex, 60 while the acetylation of IDH will have an impact on the distribution of carbon flux between the glycolysis and gluconeogenesis pathways. 55 Considering the synthesis pathways of sugars, our results showed that sucrose-phosphate synthase (SPS) was acetylated under oxybenzone treatment.…”

Cellular localization of the hybrid pyruvate/2-oxoglutarate dehydrogenase complex in the actinobacteriumCorynebacterium glutamicum

“…In actinobacteria, E2p (AceF) also forms a trimer, but a phenylalanine-containing three-residue-insertion in the C-terminal helix prevents higher order oligomerization ( 17 ). Biochemical studies with reconstituted complexes suggested that two AceF trimers form the core of the hybrid complex and are stably associated with Lpd dimers binding to the PSBD domains of AceF ( 16 , 49 ). OdhA was proposed to form hexamers and a smaller oligomer that readily associated with the AceF-Lpd subcomplex, whereas AceE appeared to have a lower affinity for this subcomplex.…”